Surface-grinding machine.



J. N. HEALD & A. M- DRAKE.

SURFACE GRINDLNG MACHINE. APPLICATION FILED JAN. 15.1915.

1.1%89. Patented May 4; 1915.

I0 SHEETSSHEET I.

W rflifm i Wm J. N. HEALD & A. M. DRAKE.

' SURFACE GRINDING MACHINE.

APPLICATION F|LED JAN- 15. I915- 1,138,28 v Patented May 4, 1915.

10 SHEETS-SHEET 2.

J. N. HEALD & A. 'M. DRAKE. SURFACE GRENDING MACHINE.

APPLICATION FILED JAN-15.1915.

Patented May-4, 1915.

I0 SHEETS-SHEET 3k J. N. HEALD & A. M. DRAKE.

SURFACE GRINDING MACHINE APPLICATION FILED JAN. 15'. 1915.

Patented May 4, 1915.

I0 SHEETS-SHEET 4.

ZWWM f W W J. N. HEALD & A. M. DRAKE.

SURFACE GRINDING MACHINE. APPLICATION FILED JAN-.15. 191s.

Patented May 4, 1915.

I0 SHEETS-SHEET 5.

Gil-D J. N. HEALD & A. M. DRAKE. SURFACE GRINDING MACHINE.

\ APPLICATION FILED JAN-15.1915. Patented May 4, 1915.

I0 SHEETS-SHEET 6.

J, N. HEALD 8L A. M. DRAKE. SURFACE GRINDING MACHINE. APIPLICATION FILED JAN- 15. 1915.

Patented May 4, 1915.

10 SHEETS-SHEET I.

Wwiaesses:

J. N. HEALD & A. M. DRAKE.

SURFACE GRINDING MACHlNE. APPLICATION FILED JAN-5x1915- Patented May 4,

l0 SHEETSSHEET 8.

QQW

QQ m

, J. N. HEALD & A. M. DRAKE.

SURFACE GRINDING MACHINE.

APPLICATION FILED JAN-15. 1915.

Patented May 4, 1915.

10 SHEETS-SHEET 9.

J. N. HEALD & A. M. DRAKE. SURFACE GRINDING MACHINE.

APPLICATION FILED JAN-15.1915.

289. Patefited May 4, 1915.

I0 SHEETSSHEET IO,

y A s as JAMES N. HEALD AND ALDEN M. DRAKE, OF WORCESTER, MASSAQEUSETTS, ASSIGNORS TO HEALD MACHINE COMP-ANY, F WORCESTER, MASSACHUSETTS, A CORPORATION To all whom/it ma concern:

OF MASSACHUSETTS.

Be it knownt at we, JAMES N. HEALD and ALDEN M. DRAKE, citizens of the United States, both residing at Worcester, inthe Further features of our invention relate to improved devices for controlling the lateral movements of th e grinding wheel and for moving the work table.

With these and other objects in view our invention further relates to certain devices,

arrangements and combinations of parts which will be hereinafte? described v and more particularly pointed out in the appended claims.

A preferred form* of our invention is shown in the drawings in which Figure 1 is a front elevation of our improved machine; Fig. 2 is a sectional detail taken along the" line 22 in Fig. 1; Fig. 3 is a rear elevation of the machine; Fig. 4 is an enlarged detail of the support for the idle pulleys; Fig. 5 is an end elevation of the machine; Fig. 6 is a top plan view thereof; Fig. 7 is an enlarged rear elevation of the wheel slide and a portion of the belt drive; Fig. 8 is a front vertical sectional view of the wheel slide taken along the line -88 in Fig. 5; Fig. 9 is a horizontal section of the bearings and support for the grinding shaft taken along the line 99 in Fig. 8; Fig. 10 is a detail elevation of the devices for manually adjusting the grinding shaft bearings, taken substantially along the line 1-()-10 in Fig. 5; Fig. 11 is an end elevation of the mechanism for raising and lowering the movable head which supports the wheel slide; Fig. 12 is a top plan view of a portion of the movable'head and its support; Fig. 13 is a detail view of a por-, tion of the-handelevating devices looking in the direction of the arrow 13 in Fig. 11; Fig. 14 is-an elevation of the upper bearing SURFACE-GRINDING MACHINE.

Patented May 4, 1915.

ApplicationfiledJ'anuary 15, 1915. Serial No. 2,467.

by the arrow 18 in Fig. 16; Fig. 19 is a sectional detail of the change gear mechanism taken along the line 1919 in Fig. 16; Fig. 20 is an enlarged detail section of the friction drive at one end of the table feeding shaft; Fig. 21 is a vertical sectional view v of the table-feed-controlling mechanism taken along the line 2121 in Figs. '1 and 16; Fig. 22 is a diagrammatic View showing the relative positions of the hand and power feed shafts; Fig. 23' is a sectional view showing the connections from the hand wheel to the table driving gear taken along the line 2323 in F ig. 22, and Figs. 24 and 25 are detail views, in front and side elevation, of a portion .of the friction connection between the table drive and the cross feed.

Referring to the drawings, our improved .grinding machine is mounted upon a base 30 (Fig. 1) having a standard 31 rigidly secured thereto by a plurality of bolts 32 (Fig. Ahead 33 is mounted .for 'vertical movement upon the standard 31 and constitutes a support for the wheel slide 34 (Fig. 7). The grinding wheel VV'is mounted upon a horizontal shaft 35 (Fig. 9) having a longitudinally extended drum 36 secured thereto.

W'heel driving mechanism.-The main power shaft of the machine is indicated at 37 (Fig. 3) and may be driven in any convenient manner. As shown in the drawings, the shaft 37 carries a pulley 38 which is driven by a belt 39 from a motor 40. The shaft 37 is also provided with a pulley 41 which drives a belt 42. The belt 42 passes around a guide pulley 43 mounted for vertical adjustment upon the standard 31 and thereafter passes around an idle pulley 44 mounted upon the movable head 33. From the pulley 44 the belt*42 passes over the drum 36 and from thence to a second idle pulley 45 mounted upon a. bracket 46 (Figs.

.4 and 7) secured to the head 33 by bolts 47.

In practice, the pulleys 44 and 45 are both commonly supported upon the bracket 46.

The pulleys 41, 43, 44 and 45 are so positioned that the runs ofthe belt 42 between the pulleys 43 and 44 and between the pulleys 45 and 41 extend in substantially vertical lines parallel to the travel of the head 33. \Vith this arrangement it will be seen that the length of the driving belt may remain unchanged, whatever the vertical position of the head 33. It will also appear that this construction enables me to use a single long driving belt between the wheel shaft and the main power shaft and that this belt is so arranged that it will have driving contact with a large portion of the circumference of the drum 36.

Head elevating mechanism.-Ref erring particularly to Figs. 7, and 11 to 14, we will a now describe the movable head and the mechanism for elevating it. The movable head 33 is provided with undercut guiding surfaces and 51 (Fig. 12) upon its rear face, which surfaces engage ways52 upon the standard 31. The guiding surface 51 is formed upon an adjustable gib 53. Clamping screws 54 (Fig. 2) extend through the gib into the head 33 and are provided with handles 55 for convenient o era-tion thereof. The screws 54 are loosene during vertical adjustment of the head and are thereafter tightened to rigidly secure the head to the standard 31 during the grinding operation.

An elevating screw 56 (Fig. 5) is support gear and is held in position in its bearing by a collar 610 and an adjusting nut 620 at its upper end. Relative rotation of the sleeve 56 and the sleeve 59 is prevented by the key 630 fixed in theshaft 56 and sliding in a keyway 640 in the sleeve 59. The beveled gear 60 engages asecond beveled gear 61 (Fig. 11) mounted upon a shaft 62 extending horizontally through the base 30. to the front of the machine. At ts forward end, the shaft 62 carries a spur gear 63 engaging a second spur. gear 64 (Fig. 13) upon a short stud shaft 65. The shaft 65 1s squared at its outer end, asindicated at 66, for the reception of an operating handle.

The operation of the head elevatlng devices will be apparent from the detailed description thereof.

- While it is possible to finally ad ust the machine for certain purposes by the use of the elevating devices just described, 1t is my intention to use these devices merely for rough or approximate ad ustment, the final close adjustment being made by an auxiliary adjusting mechanism which will now be described.

A um'liary vertical adjustmnt-lieferring particularly to Figs. 9 and 10, the wheel shaft 35 is mounted in bearings 70, 71 and 72. The bearing is mounted in an eccentric sleeve 73 rotatable in the wheel slide 34.

At its upper end the shaft 7 8' isconnected by beveled gears 79 and 80 to a cross shaft 81 having a hand wheel 82 (Fig. 5) upon its outer end. The hand wheel 82 may be graduated around its circumference, as shown in Fig. 1, and the slide 34 may carry a zero line upon a stud 82* adjacent the hand Wheel 82. The arm 74 may of course be .formed integral with both sleeves 73and if so desired.

Reference to Fig. 10 will show the extreme eccentricity of the sleeve 75 the centers of the shaft 35 and the sleeve 75 being about 1" apart, so that the axis of the shaft.

35 moves in the arc-of a 2" circle when the sleeve 75 is adjusted. Adjustment of the bearing to carry the axisof the shaft above or below its normal position is found to be ample for practical purposes, and for this range of movement the arc is substantially a straight line and the vertical move; ment is substantially proportional to the angular movement of the hand wheel 82 as measured by the graduations thereon.

Not only may very accurate adjustment be thus obtained but furthermore the elevation or depression of the shaft through angular adjustment of the eccentric sleeves in close fitting bearings avoids the lost motion between screw and nut and the varying friction of a vertically sliding member, and also avoids the necessity of raising or lowering the great mass of the movable head and wheel slide for fine adjustments, all of which is unavoidable in using elevating mechanism trically mounted bearings in the wheel slide 34. This slide consists of a heavy trans versely extending casting having inclined bearing surfaces 85 and 86 (Figs. 7 and 8 engaging a correspondingly shaped way 8 formed integrally with the movable head .89 (Fig. 8) inclosing the upper portion of the grinding wheel. A suitable cover plate 90 (Fig. 7) incloses the connections fromthe hand wheel 82 to the eccentric sleeve 75, and at the left hand end, as viewed in Figs. 5 and 6, the wheel slide is provided with an extension or cover plate 91 for protecting the end of the supporting ways 87.

For moving the grinding wheel transversely of the table we provide the mechanism shown in Figs. 15, 16 and 17. This mechanism comp ises a horizontal shaftlOO (Fig. 15) having one end mounted in antifriction thrust bearings 101 in a casing 102 secured to the end of the slide-supporting portion of the movable head 33.

The shaft 100 is threaded to engage a nut 103 (Fig. 8) secured to the wheel slide 34.

A beveled gear 104 (Fig. 15) is mounted on the end of the shaft 100 and engages a second beveled gear 105 upon the upper end of a vertical-shaft 106. At its lower end the shaft 106 has a sliding key connection with a sleeve 107 mounted to rotate in a gear box 108 mounted upon the side of the bed 30. Beveled pi-nions 109-110 connect the sleeve 107 with a horizontal shaft 111 extending transversely through the bed to the front of the machine.

Near the forward end of the shaft 111 spur gears 112 and 113 are mounted for free rotation thereon, these gears being separated by a thin cylindrical shell 114 surrounding the shaft 111 between the gears. Upon theiradjacent faces the gears 112 and 113 are provided with clutch teeth adapted to engage corresponding teeth upon a sliding collar 115 (Fig. 16) mounted between the gears.

The position of the collar 115 is controlled by a rod 116 (Fig. 15) having a knob 117 at its outer end. At its inner end the rod 116 is slotted to 'receive a cross key 118 113 to the shaft 111, or, n. desired, the 001- lar may be placed in a neutral position be: tween the gears.

The gear 113 engages a pinion 120 f5rmed upon the end of a sleeve 121 rotatable upon a fixed stud 122, and the gear 112 engages a pinion 123 mounted upon the sleeve 121.

The gear 123 also meshes with a gear 124 upon a short shaft 125, upon the outer end of which is mounted a hand wheel 126. These connections constitute means for feeding the wheel slide manually transversely of the table, with either a coarse or a comparatively fine feed.

In grinding operations of the character for which this machine is designed, the

usual hand feed of the wheel takes place after the table reaches its limit of travel, at which point the wheel is given a feeding movement of considerable magnitude. To accomplish this coarse feed, the gear 112 is connected to the shaft 111. At other times it is necessary to dress the face of the wheel, for which purpose a slow continuous feed is desired and for dressing the wheel I utilize the fine feed connections through the pinion 120 and the gear 113.

- When the power feed is in use the clutch collar may be placed in neutral position as above mentioned leaving the hand wheel and the gears connected theretomotionless.

Power cross feed of wheel sZz'de.-For rotating the shaft 111 by power, I provide a ratchet wheel 130 (Figs, 1 and 15) keyed to the end of the shaft 111 and secured in position thereon by a nut 131,. A reversible pawl 132 is pivotally mounted upon a disk 133 in position to engage the teeth of the ratchet wheel 130. The pawl is retained in either of its operative positions or in neutral position by a spring-pressed plunger in the disk 133 (Fig. 15).

is provided with gear teeth 139 positioned to engage a sliding rack 140 (Figs. 16 and 17).

The rack 140 is slidably supported in a guide 141 secured to the outer face of the bushing 136. At its opposite end the rack is connected to a crank pin 142 (Fig. 21) adjustable radially in a slot 143 (Figs. 1 and 21) in a disk 144. The crank pin is secured in adjusted position by a nut 145 having a handle 146.

The disk 144 is rotated through substan- F tially one complete revolution at each end of the table travel, these rotations alternat-v ing in direction. The mechanism for thus intermittently rotating the disk 144 will be I hereinafter described, Such rotation of the 45 front of the machine and having a small hand wheel 167 secured to its forward end.

' disk 144 and crank pm 142 produces interreversible pawl 132 will pass freely over the mittent reciprocating movements of the rack 140 which in turn rotates the disk'133 alter-' nately in opposite directions.

During the movement 1n one direction the teeth on the ratchet wheelbut when moving in the opposite direction the pawl 132 will engage the teeth on theratchet wheel and will rotate the shaft 111 and its connected mechanism to feed the grinding wheel W transversely of the table.

Table speed-changing and reversing-mechanism.-The main power shaft 37 (Fig. 3) carries a small pulley 150 in addition to the pulleys 38 and 41 previously described. The

pulley 150 is belt connected to drive a pulley 151 upon a short shaft 152 (Fig. 16) mounted in. a gear box 153 (Figs. 3 and 18) secured to the rear side of the bed 30. The

'-: shaft 152 carries a worm 154 (Fig. 18)

which engages a worm wheel 155 on a horizontal shaft 156 extending longitudinally of the gear box and having fixed thereto change gears 157% 157 b and 157 These change gears mesh with corresponding gears 158*,

I 158*, and 158 loosely, rotatable upon a hollow shaft 159 (FigJ19) supported in bearings in the gear box 153 and parallel to'the shaft 156. Y Y

The change gears 158*, 158 and 158 are selectively connected to the hollow shaft 159 by a sliding key 160 pivoted to a rod 161 sliding within the shaft 159. The key is movable by means of the rod into position 1 to engage akeyway withih either one of the change gears and it is yieldingly forced outward by a spring 162. A cross pin 163 engages a keyway in the hollow shaft and pre-. vents relative rotation of the rod and shaft. At its outer end, the rod 161 is\ provided with circumferential rack teeth 164 positioned for engagement by a pinion 165. The pinion 165 is formed upon the end of a-shaft 166 (Fig. 16) extending horizontally to the By proper manipulation of the hand wheel 167 the rod 161 may be moved longitudinally to connect either one of the pairs of change gears to the hollow shaft 159.

'member 171 (Figs. 18 and 21) mounted to slide longitudinally upon a shaft 172. The

At its forward end, the shaft 17 9 is provided with a lever 180 (Fig. 1) projecting upwardly in the path of dogs 181 secured to the side of the table 182. These dogs alternately engage the lever 180 as the table reaches its limit of travel and-through the shaft 179 move the rod 174 longitudinally in one direction or the other. As the rod 174 is moved longitudinally it carries the collar 175 with it .and compresses one of the springs 177. At the-same time one of a pair of latches 183183 pivoted upon the gear box 153 engages one end of the sliding yoke 171 and prevents movement thereof until a cam block 184 carried by the 'rod 174 engages and lifts the end of the latch to release the sliding yoke. The compressed spring 177 then acts to move the sliding yoke longitudinally, thus changing the driving relation of the clutch collar 170 to the gears 168 and 169. 1

1 The devices above described for varying the speed and reversing the direction of travel of the work table'constitute no part of my invention and any other suitable speed changing and reversing mechanism may be substituted therefor.

Table reciprocating mechanism.The beveled pinions 168 and 169 (Figs. 16 and 21) are in constant engagement with a beveled gear 190 mountedupon the end of a horizontal shaft 191. The shaft 191 extends freely through the hub of a spiral gear 192 and has fixed at a point beyond the hub one member 193 of a friction clutch. The member 193 is provided with an expansible friction ring 194 which when expanded engages a flange 195 formed upon the side of a gear 196 secured to the hub of the spiral gear 192. A clutch operating collar 197 is slidable upon the hub of the clutch member 193 and is controlled by an arm 198 pivoted at $39 and controlled by an operating handle 01 h Referring to Figs. 22 and 23 we make the following provision for feeding the table by hand. The gear 196 above described meshes with the gear 201 upon a horizontal shaft 202 mounted in fixed hearings in the frame of the machine and having a second gear 203 secured thereto. The gear 203 meshes with a pinion 204 upon a second new short horizontal, shaft 205 extending for.- -wardlythrough the framework and having a hand wheel 206 upon its forward end. Through this train of reducing gearingthe operator is enabled to turn the spiral gear 192 to move the table, through connections to be described, and it should be noted that during this operation the spiral gear 192 turns freely upon the shaft 191. Accordingly it is not necessary for the operator to rotate the shaft 191 or the beveled gears 190, 168 and 169 when moving the table by hand.

Power cross-feed oonnectz'ons.At the forward end of the shaft 191. provision is made for frictionally engaging and driving the rack-operating disk 144 previously described. For this purpose a driving member 210 (Fig.21) is supported within a bearing 211, the member 210 being keyed to the forward end of the shaft 191 and providing a support therefor The member 210 is retained in the bearing 211 by a collar 212 and a nut -213; The hub of the member 210 is reduced at its front end to form a cylindrical projection 214 upon which is rotatably supported the hub 215.

i of a plate 216 having the disk 144 fixed to its outer surface. A iction ring 217 (Figs. 21, 24 and 25) is mounted torotate with the plate 216 and frictionally engages an annular flange 218 upon the driving member 210. The friction band 217 is severed at one point in its circumference, as shown in Fig. 24, the two parts being yieldingly pressed together by a spring 219 mounted upon a stud 220 extending loosely throughone per 7 tion of the friction ring and threaded into ends of the friction ring, thereby enlarging the second portion. "A radially extendin pm 221 is pivotally mounted in a cylindrica recess formed between the two ends of the friction ring, the pin221 being positioned to engage a stop 222 (Fig. 1 6) as the ring is rotated. e

The operation of this device is as follows :'The pin 221 normally engages the stop 222 and acts as a lever to se arate the the ring. and releasing from driving rengagement with the flange 218 upon the driv- 1ngmember 210. When the rotation of the shaft 191 is reversed by the engagement of one of the dogs upon the table with thereversing lever 180, the pin 221 willbe moved from its stop thereby permitting the friction band to contract and to come into driving engagement with the flange 218. The frick tlon ring together with the plate 216 and the.

' .disk 144 will thereafterrotate with the drivin g 'member 210 until the parts have substantially completed one revolution when the pin 221 will again engage the stop 222 upon the opposite side thereof and the frict1o n r1ng will be again released from the driv ng flange, The plate 144 will therefore ionin receive substantially one revolution at each .reversal of the table and these revolutions will be alternate in direction. Each revolution of the disk 144 in either direction causes 192 .whichmeshes with and drives a cooperating spiral gear 230 (Fig. 16) loosely mounted upon a, shaft 231 which is diagonally disposed with relation to thetravel of the table and is supported in fixed bearings 232 secured to the bed 30. f The spiral gear 230 is frictionally connected to the shaft 231 by the devices shown in Fig. 20, which include'a leather friction washer 233 engaging the hub of the gear 230 and forced into engagement therewith by a spring-pressed plate 234. The plate 234 has studs 235 mounted on the rear face thereof and received within recesses 236 in a collar 237 ke ed to the end of the shaft 231 and-secure thereon by lock nuts 237.

Spiral springs. 238 within thev recesses 236' 1 force the plate 234 and the friction washer against the hub of the gear 230, The shaft 231 is thus normallydriven by the gear 230 but may yieldwith relation thereto should any pbstruetion interfere with the table trave A spiral gear 239 (Fig. 16) is slidably mounted near the forward end of the shaft 231,- said gear being provided with anti- .friction thrust bearmgs 240 at each end thereof, said bearin s being yieldingly held in position by thic leather washers 241. The spiral gear 239 directly engages a rack 242 (Figs. 16 and 21) secured to the lower side of the table 182. The leather washers 241 are in nded to have a substantial cushthe ta le travel, thereby relieving somewhat the strain upon the teeth of the rack 242 and the spiral gear 239. Furthermore the sliding connection of the gear 239 and the shaft 231 prevents possible longitudinal .moveinent of the shaft 231 by the reversal strain,

e ect at the moment of reversal of whichmovement might injure the teeth of the spiral gears 230 and 192. p

Operation-The operation of our im proved grinding machine has been indicated at various points in the preceding description and need be only briefly summarized at this point. The work is secured upon the upper surface of the table 182 in any convenient mannenand the grinding wheeliW is'brought to approximate vertical position by the use of an operating handle upon the squared end 66 (Fig.11) of the shaft'65, efietive t r ugh onne ti ns to efute a shaft by manipulation of the hand wheel 82 (Figs. 6 and 10). The knob 117 (Fig. 15) may then be pulled out to connect the cross-feed hand-wheel 126 through. the gears 124, 123 and 112 to the shaft 111,

which in turn is connected through the shaft 106 to the cross-feed screw 100. Manipula- I tion of the hand wheel 126 is then effective to move the grinding wheel W to its proper transverse position.

Should a finer hand cross-feedbe desired,

the knob 117 may be pushed in to engage the gears 120 and 113 with the shaft 111. When the wheel is properly positioned transversely the knob 117 may be moved to place the clutch collar 115 in neutral position this disconnecting the hand wheel from the shaft 111. I

The desired table speed can be determined by selectively operating the changegear hand-wheel 167 (Fig. 16) which controls the sliding key within the change gears 158",

158", and 158. The table 182 may be moved longitudinally by the hand wheel 206 (Fig.

23) to the desired starting position, after which the power feed may be thrown in by depressing the friction clutch lever 200. (Fig. 21). The table will thereafter be reciprocated with an automatic reversal at each end of its travel and at each reversal the cross feed rack 140 (Figs. 16 and 17) will be actuated to feed the grinding wheel transversely of the table.

Having thus described our invention it will be evident that changes and modifications may be made therein without departing from the spirit and scope thereof as set forth in the claims and we do not wish to be otherwise limited to the details herein disclosed, but

What we do claim is 1. A grinding machine having in combination a movable work table, a grinding wheel and shaft supported above said table in a vertically movable head, means for elevating saidhead, and additional means for vertically adjusting said wheel and shaft relative to said table, said additional means comprising eccentric bearings for said shaft in said head, and manually operated devices for angularly moving said bearings.

2. A grinding machine having in combination a-movable work table, a grinding wheel and shaft supported above said table in a vertically movable head, means for elevating said head, and additional means for vertically adjusting said wheel and shaft relative to said table, said additional means comprising eccentric bearings for said shaft in said head, and manually operated devices for angularly moving said bearings, the axes of said shaft and said bearings being separated a substantial distance and being so relatively disposed that angular movement of said bearings will cause substantially proportional vertical movement of said shaft.

3. A grinding machine having in combination a movable work table, a grinding wheel and shaft supported above said table in a vertically movable head, means for elevating said head, and additional means for vertically adjusting said wheel and shaft relative to'said table, said additional means comprising eccentric bearings for said shaft in said head, and manually operated devices for angularly moving said bearings, said devices comprising a gear fixed to said bearings, a hand wheel on said head, and driving connections from said hand wheel to said gear.

4. A grinding machine having in combination a movable work table, a grinding wheel and shaft supported above said table in a vertically movable head, means for elevating said head, and additional means for vertically adjusting said wheel and shaft relatively to said head, said means comprising an eccentric. bearing for 'said shaft, a second eccentric bearing alined with the first bearing, and means to angularly move said bearings simultaneously.

5. A grinding machine having in combi- I nation a movable work table, a grinding wheel and shaft supported above said table in a vertically movable head, means for elevating said head, and additional means for vertically adjusting said wheel and shaft relatively to said head, said means comprising an eccentric bearing for said shaft, means to angularly adjust said bearing, a. second eccentric bearing alined with the first bearing, and an arm connecting said bearings and constraining them to. move simultaneously.

6. A grinding machine having in combination a bed, a table movable on said bed. a standard supported by said bed, a movable head vertically adjustable on said standard,

and having guiding ways formed thereon with the front bearing surface thereof inclined rearwardly downwardly, and a wheel slide having a correspondingly inclined bearing surface cooperating with said ways and said inclined surface.

7. A grinding machine having in combi-- wheel slide movable horizontally on said head, a grinding wheel and shaft rotatably mounted in horizontal hearings in said slide,

and means for rotating said shaft, said means comprising a main shaft mounted in the bed, a driving pulley thereon, a guide pulley on said standard, means to adjust said guide pulley vertically and to retain said pulley in adjusted position, a pair of guide pulleys mounted on the head and movable therewith, a drum on the Wheel shaft, and a single long belt connecting all of said pulleys and said drum.

- 8. A grinding machine having in combi nation abed, a work table movable on said bed, a standard supported on said bed, a

head movable vertically on said standard, a wheel slide movable horizontally on said head, a grinding-wheel and shaft rotatably mounted in horizontal bearings in said slide,

and means for rotating said shaft, said -means comprising a main shaft mounted in the bed, a driving pulley thereon, a pair of guide pulleys mounted on the head and movable therewith, a third guide pulley mounted on a pivot secured to said standard near its upper end, a drum on thewheel shaft, and a single long belt connecting said pulleys and drum, said driving pulley and said guide pulleys being so positioned that the runs of the belt from the driving pulley and the fixed guide pulley to the movable guiding pulleys are substantially vertical, whereby vertical adjustment of the head requires no change in the length of the driving belt.

9. A grinding machine having in combination a bed, a table longitudinally movable on said bed, a standard supported on said bed, a movable head vertically adjustable on said standard, a grinding wheel and shaft supported'on said movable head, separate means for course and fine adjustment of said wheel and shaft vertically, manually-operated means for fast and slow adjustment of the wheel and shaft longitudinally, and additional power-actuated means for adjusting .said wheel and shaft longitudinally.

10. A grinding machine having in combination a bed, a table movable on said bed, a

standard supported by said bed, a movable head vertically adjustable on said standard, guiding ways on said head, a wheel slide longitudinally movable on said Ways, and

. means for moving said slide, said means comprising fast and slow speed hand-operated devices, means for connecting either de- -vice to move the slide, and intermittentlyoperated power-actuated devices for automatic feeding of the wheel slide.

11. In a grinding machine, a table, a rack on the table,a spiral gear engaging said rack, a diagonally-disposed shaft upon which said gear is slidably mounted, and cushioning members disposed at each end of said spiral gear to relieve the end thrust thereon when the table is reversed.

12. In a grinding machine, a table, a rack on the table, a. spiral gear engaging revolution at each reversal of the table 'travel.

said rack, a diagonally disposed shaft upon which said gear is mounted, a second gear loosely supported onsaid. shaft, means for I driving-said gear, and friction connections between said gear and said diagonal shaft.

13. In a grinding machine, a'table, a rack on the table, a spiral gear engaging said rack, a diagonally-disposed shaft upon gear upon the diagonal shaft, a transversely extending horizontal shaft disposed below said diagonal shaft, a third spiral gear meshing with said second gear and rotatable upon the transverse shaft, a friction clutch between said shaft and said third gear, and means for rotating said transverse shaft,

said means including devices for automati-' cally reversing said shaft and for varying the speed thereof.

15. In a grinding machine in combination a table, a rack on said table, a shaft, connections from said shaft to said rack, means to' drive said shaft in either direction by power, and means to move the table manually through said connections but independently of said shaft.

16. In a grinding machine, a shaft, table I driving mechanism, means for frictionally engaging and driving said mechanism from said shaft, a wheel slide, mechanism for moving-the wheel slide longitudinally, and connections for intermittently actuating said latter mechanism from said shaft.

17. In a grinding machine, a table, a grinding wheel, mechanism for feeding the wheel transversely of the table, and devices for intermittently actuating said mechanism, said devices comprising a pinion, a rack engaging said pinion, a crank pin forming a pivot for said rack and adjustably mountedon a crank disk, and means for intermittently rotating said disk substantially one 18. In a grind ng machine, a table, a grinding wheel, mechanism for feeding the Wheel transversely of the table, and devices for intermittently actuating. said mechanism said devices com risin a inion a rack engaging said pinion, a crank pin forming a pivot for said rack and adjustably mounted on a crank disk, means for intermittently rotating said disk, and an'anguset our hands, in the presence of two sublarly movable support for said rack mounted scribing witnesses. H concentrically with said pinion and effective JAMES N. HEALD.

to hold said rack in operative engagement ALDEN M. DRAKE. 5 with said pinion during the rotation of the Witnesses: A v

crank disk and pin. CHAS. T. HAWLEY,

In testimony whereof we have hereunto C. FORREST WESSON. 

